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How to Grow Yacon

Smallanthus sonchifolius

Half Hardy Warm Season Single Harvest

When to Start

Sow indoors 6 weeks before last frost, or direct sow outdoors after frost risk has passed and soil reaches 12°C.

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Growth Stages

Sow seeds
Germination ~21d
Flowering ~150d
Harvest ~180d

Approximate days from start

Care Essentials

  • Apply a balanced general-purpose feed monthly from June to August. Avoid high-nitrogen feeds which promote foliage at the expense of tuber development.
  • Yacon is grown from rhizome offsets (crown divisions), not seed. Start indoors in pots from March, plant out after last frost in May. Plants grow tall (1.5-2 m) and may need staking in exposed sites. Save a few small rhizomes each year for replanting.

Companion Planting

Growing Conditions

Min. soil temperature: 12°C+
Germination temperature: 15–25°C

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Spacing & Planting

Plant spacing 75 cm
Row spacing 90 cm
Sow depth 5 cm
Mature height 200 cm
Mature spread 80 cm

Space 60-90 cm apart. Plants grow tall (up to 2 m) and bushy by late summer, so allow room for air circulation. A catch crop of salads can be grown between plants early in the season.

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Care Guide

Feeding
Apply a balanced general-purpose feed monthly from June to August. Avoid high-nitrogen feeds which promote foliage at the expense of tuber development.
Watch for
  • Slugs on young shoots
  • Wind damage to tall stems
  • Frost damage to foliage

Pests & Diseases

Pest Slugs and Snails

Identification: Irregular holes in young leaves, slime trails visible on soil and foliage, damage worst in wet weather

Organic treatment:
  • Beer traps
  • Copper tape around pots
  • Evening patrols
  • Nematode biological control (Nemaslug)
Chemical treatment:
  • Ferric phosphate pellets
Disease Crown Rot

Symptoms: Soft, mushy crown tissue during storage, foul smell, spreads to stored rhizomes

Treatment: Discard affected material, ensure good air circulation during curing, store in barely-damp compost

Prevention: Cure tubers in dry conditions before storage, avoid damage during harvest, store in cool frost-free conditions

Growing Conditions

Min. soil temperature12°C
Germination temperature15–25°C
Base growth temperature10°C
Min. daylength to start12h
Photoperiod sensitivityday neutral

Frequently Asked Questions

How far apart should I plant Yacon?
Plant Yacon 75cm apart with 90cm between rows.
When can I harvest Yacon?
Yacon is ready to harvest approximately 150 days after transplanting.
Is Yacon frost hardy?
Yacon is classified as Half Hardy.

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